*{
    margin: 0;
    padding: 0;
    list-style: none;
    
}
.header{
    width: 800px;
    margin: 0 auto;
    display: flex;
    height: 40px;
    align-items: center;
    

    
}
.header >div{
    margin: 0 10px;
}
.header-bottom{
    width: 300px;
    margin: 50px auto;
}
.ad{
    display: none;
}
